Effect of Decaffeinated Green Tea Polyphenols on Body Weight and Precocious Puberty in Obese Girls: A Randomized Controlled Trial

Background: Obesity has been reported to be an important contributing factor for precocious puberty in girls. Green tea polyphenols showed the effect on weight reduction in obese adults. This study was to examine the effectiveness and safety of decaffeinated green tea polyphenols (DGTP) on ameliorating obesity and early sexual development in obese girls. Methods: This is a double-blinded randomized controlled trial. Overweight or obese girls aged 6-10 years old were recruited and randomly assigned (1:1) to receive 400mg/d DGTP or isodose placebo orally for 12 weeks. During this period, all participants received the same instruction on diet and exercise from trained dietitians. Anthropometric measurement, secondary sexual characteristics, B-scan ultrasonography of uterus, ovaries and breast tissues, and related biochemical parameters were examined and assessed at pre- and post-treatment. Findings: Between August 2018 to January 2020, 62 obese girls (DGTP group n=31, control group n=31) completed the intervention and were included in analysis. After the intervention, the fat mass, percentage of body fat (PBF), serum uric acid (UA), and the volumes of ovaries decreased significantly in the DGTP group, and no such differences were observed in the control group. The body mass index and waist-to-hip ratio significantly decreased within both groups, but no significant differences were found between groups. After controlling confounding factors, DGTP showed a significantly decreased effect on ΔPBF, ΔUA, and Δovarian volumes in obese girls. The levels of sex hormones increased in both groups but overall remained far from the standards of girls’ sexual development initiation. No significant changes were found in serum trace elements, hepatic and renal function, and complete blood count post treatment, and no side effect was reported during the whole period. Interpretation: Decaffeinated green tea polyphenols have beneficial effects on ameliorating obesity and postponing early sexual development in obese girls without any adverse effects. Trial Registration: This trial is registered with Clinical Trials.gov, NCT03628937. Funding Statement: The National Natural Science Foundation of China (No. 81773407). Declaration of Interests: We declare no competing interests. Ethics Approval Statement: This study was approved by the Ethics Committee of Xinhua Hospital (Shanghai, China).